"Ethereum has two types of accounts: Externally Owned Account (EOA) and Contract Account (CA). EOAs are controlled by a private key while CAs are controlled by the smart contract code contained in them. EOAs have always been more privileged than CAs because only EOAs can start transaction execution by paying gas. Account Abstraction (AA) is a proposal that allows a contract to be a โtop-levelโ account, like an EOA, that can pay fees and start transaction execution."